What does anyone gain from items being exclusive for exclusivity-sake?
Raiding gear and even more so PvP-gear being exclusive is fine in my book - its the reward for putting effort into something. Earning the "right" to wear that gear by doing something a bit more outstanding than doing a 15-minute-event-quest.
Its news to me that gear gains anything lookwise (you know, the important part about gear/clothes/glamour: does it look good?) by being exclusive. The only vanity-effect that exclusitvity would have is "Haha, I have this [because I played this game last year and did a 15-minute-event-quest] and you dont and you can never get it!"
...whats won by that?